Mostra la font per a Regex

 /text/   Case sensible
 /text/i   Not Case sensible

 [^>] Any character except >
 ? lazy search (as small as possible)
 :.+?: any amount of character between : and : (but at least one)
 :.*?: any amount of character between : and : ("::" is ok)
 :[^:]: should be the same

 () Exports data to $match[1], second () to $match[2] ...etc.
 $match[0] is everything
 

There are 11 characters with special meanings (have to be escaped with "\"): 
 the opening square bracket [
 the backslash \
 the caret ^
 the dollar sign $
 the period or dot .
 the vertical bar or pipe symbol |
 the question mark ?
 the asterisk or star *
 the plus sign +
 the opening round bracket (
 and the closing round bracket )


<pre>
preg_match_all('/\[(.*?) (.*?)\].*?: (.*?);.*?idle=(.*?)% user=(.*?)% system=(.*?)% iowait=(.*?)%/i', $text, $match);

for ($i = 0; $i < count($match[1]); $i ++)
{
 $file = "nagiossnap/" . $match[3][$i] . ".txt";
 file_put_contents($file, $match[1][$i] . "\t" . $match[2][$i]. "\t" . $match[4][$i]. "\t" . $match[5][$i] . "\t" . $match[6][$i] . "\t" . $match[7][$i] . "\n", FILE_APPEND | LOCK_EX);

 print $match[1][$i];
 print $match[2][$i];
 print $match[3][$i];
 print $match[4][$i];
 print $match[5][$i];
 print $match[6][$i];
 print $match[7][$i];

(...)
</pre>
Example taken form here: http://esa.espai.de/Logica_client-logica



Nice reference guide here: http://www.regular-expressions.info/reference.html